1. Field of the Invention
The present invention relates to a surgical clip, and more particularly to a hemostatic clip to be applied to blood vessels.
2. Background of the Art
Ligation or occlusion of veins, arteries or blood vessels has been a necessary part of surgical procedures for many years. Initially, surgeons used thread or suture material to tie a blood vessel prior to severing the vessel. This procedure required both skill and time on the part of the surgeon to properly close the vessel. In many instances, assistance of a nurse or attending surgeon was necessary and typically, a severed blood vessel would require closure on both sides of a severance site before actual cutting could take place. The advent of surgical clips and clip appliers has greatly enhanced this procedure.
Surgical clips are now commonly used and various types of surgical hemostatic clips are described in U.S. Pat. Nos. 4,976,722; 4,844,066; 4,702,247; 4,188,953; 3,867,944; and 3,363,628.
Many factors are critical to the design of a surgical clip. Among these, it is important that the clip not slip or become dislodged from a blood vessel after the blood vessel is severed. In that instance, blood will immediately begin flowing into the surgery site through the unclamped vessel requiring the operation be delayed while the critical vessel is located and reclamped. Depending on the type and location of the surgery, locating the vessel may be difficult and the time delay could cause medical complications to the patient.
Similarly, a clip must be designed to fully and completely close about a vein, artery or blood vessel and completely stop the flow of blood through these pathways. A clip which does not completely occlude the flow of blood is useless for its intended function. In addition, if the clip is of such a size or is designed in such a manner that during deformation about a vessel a portion of the vessel is allowed to extend beyond the tips of the clip legs, the clip will obviously not completely restrict the flow of blood and similar serious problems could arise. Consequently, besides insuring that the vessel is completely trapped within the clip, the clip must be designed such that when it is completely formed about a vessel the flow of blood through the vessel is completely precluded.
Generally, surgical clips are U-shaped or V-shaped members having two legs joined at an apex or crown portion and spaced apart at the opposite end. The inside or tissue-engaging surfaces of the clip legs may be treated in some manner, such as having spaced of grooves, in an attempt to improve the occluding functions of the clip and restrict movement of the clip after the clip has been deformed about a blood vessel. See, e.g., U.S. Pat. No. 4,799,481 to Transue et al.
Despite known clip designs, an improved clip is needed to provide optimum vessel occlusion and clip retention on tissue.